Production at the facility in Wilton on Teesside ground to a halt in February 2015 following major concerns over profitability.
CropEnergies, which owns the plant, said it would give the facility a trial run from July 2016 ‘at the latest’.
A spokesman said: “The plant has been temporarily closed since February 2015.
“During this time, numerous technical modifications have been carried out to improve the reliability and energy efficiency of the plant.
“These improvements are to be intensively tested now.”
The plant opened in 2009 but was mothballed in 2011 due to US competition and a drop in demand.
Since then it has been a stop-start affair, with the German owners blaming rising energy costs and a poor wheat harvest.
Ensus, based in Yarm, has an annual capacity of 400,000 cubic metres of bioethanol and 350,000 tonnes of dried protein animal feed (DDGS).
The plant uses more than 1 million tonnes of feed wheat each year, which is sourced in the UK and across Europe.